Painted Cliffs and Ryan Moore bounded clear in the GAIN Railway Stakes at the Curragh.
Down the field on debut before getting off the mark at Leopardstown just nine days ago, the Canford Cliffs colt was a 7-1 shot to provide Aidan O'Brien with a 12th triumph in this Group Two contest.
Richard Hannon's British raider Log Out Island took the field along, looking to go one place better than when runner-up in the Norfolk Stakes at Royal Ascot last week, with Painted Cliffs his nearest pursuer.
There was little to choose between the pair passing the two-furlong marker, but Painted Cliffs quickly asserted and was well on top at the finish.
Jessica Harrington's Rockaway Valley was the 11-8 favourite having had the winner well behind him here last month, but was under pressure some way from home before boxing on to beat Log Out Island to the runner-up spot.
Moore said: "We took it up far too early really, but he's a nice horse and he'll improve.
"All Aidan's two-year-olds are running great at the moment."